Two-stage inflation aspirator



Aug; 12, 1969 cQJ. GREEN ET AL 3,460

TWO-STAGE INFLATION ASPIRATOR 5 Sheets-Sheet 1 Fil d Oct. 27. 19s? INVENTORS' N BY LYLE D. GAL Elf/TH M 5 M c. J. GREEN ET AL TWO-STAGE INFLATION ASPIRATOR Aug. 12, 11969 5 Sheets-Sheet 2 Filed Oct. 27. 1967 Aug. 12, 1969 r c. J, GREEN ETAL 3,460,746

" TWO-STAGE INFLATION ASPIRA'I'OR Filed Oct. 27. 1967 5 Sheets -Sheet 3 INVENTORS CHARLES GREEN f LAN K FOAS'VTHE OHN M GOODE LYLE D. GALB/Wl/TH $486 46 r F 2] ATTORNEYS 5 smu -sheet 4 WHY ATTORN EYS jpjm E p. GZBRAITH C. JLGREEN ET AL TWO-STAGE INFLAT ION ASPIRATOR Aug. 12, 1969 Filed Oct. 27, 1967 Aug. 12, 1969 cg. J. GREEN ET AL 3,46

TWO-STAGE INFLATION ASPIRATOR Filed on. 27. 19a? s Sheets-Sheet 5 M 9A. 64 A22 INVENTORS' CHARLES J. GREEN ALAN K FORSYTHE JOHN W. GOODE L LE 1). GA LBRAITH 8 L I I ATTORNEYS United States Patent 3,460,746 TWO-STAGE INFLATION ASPIRATOR Charles J. Green, Vashon Island, Alan K. Forsythe, Seattle, John W. Goode, Mercer Island, and Lyle D. Galbraith, Redmond, Wash., assignors to Rocket Research Corporation, Seattle, Wash., a corporation of Washington Filed Oct. 27, 1967, Ser. No. 678,565 Int. Cl. F04f 5/22, 5/48; F16k 15/20 U.S. Cl. 230-104 20 Claims ABSTRACT OF THE DISCLOSURE -A first stage ambient air aspirator discharges into a second stage ambient air aspirator which in turn discharges into an inflatable object. A separate valve is provided for each stage. The back pressure in the object operates to automatically close the second stage valve when the back pressure in the object exceeds the pressure of the second stage aspirated air stream. Inflation is completed by the first stage alone. The two valves prevent deflation through the asiprator when inflation has been completed.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to inflation aspirators, and more particularly to multistage aspirators adapted for rapid inflation of various inflatable objects; such as escape chutes, rafts, and the like.

DESCRIPTION OF THE PRIOR ART A rapid inflation rate is a requirement of many in-' flatable devices, particularly those used with emergency objects, such as escape chutes and rafts.

Prior art aspirating devices aiming towards rapid inflation of inflatable objects have generally taken one of two forms. The first form is exemplified by the aspirator shown in the patent to Neigel, 2,859,908. An aspirating gas is introduced as a high velocity stream into a venturi nozzle adapted to discharge into the object being inflated. The upstream end of the nozzle is open to the surrounding air and the high velocity gas stream creates a suction to draw or aspirate ambient air into the stream for the purpose of increasing its volume. When the object is sufliciently inflated, and delivery of the aspirating gas has ceased, a check valve in the nozzle is closed by back pressure to prevent deflation.

A second form of inflation aspirator is shown in the patent to Crawford et al., 2,772,829. It is adapted for use in installations wherein the combined stream of aspirating gas and aspirated air, although of a high volume, is of an insuflicient pressure to fully inflate the object. A check valve is provided to be closed by back pressure when the pressure in the object being inflated reaches the pressure of the air and gas stream. Aspiration of ambient air is stopped. However, the gas flow is continued and it, by itself being of a higher pressure than the gases in the object, continues to inflate the object.

SUMMARY OF THE INVENTION This invention is directed to the technique of using an aspirator to inflate an object by filling the object at a more rapid rate than in either of the foregoing devices while still providing a high pressure fluid for inflating the object to a desired pressure. To accomplish this, a two-stage aspirator in employed. The aspirating fluid for the first stage is obtained from a high pressure source and the stream of aspirating fluid and 3,460,746 Patented Aug. 12, 1969 aspirated air leaving the first stage nozzle is used as the aspirating fluid for the second stage nozzle. In this manner a high volume, low pressure fluid stream is used to inflate the object up to a desired pressure level less than the final pressure. When this lower level is reached the second stage of the aspirator is valved shut and inflation is completed by the effluent of the first stage nozzle only.

As another feature of this invention, a telescopic aspirator is used which may be stored very compactly in a nonactive condition within the inflatable ob ject during storage of said object in a folded condition. When activated, however, the nozzles of both stages are automatically extended to produce a more eflicient nozzle shape and thus provide better flow characteristics for more rapid inflation of the object and better mixing of the gas and air.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is an isometric view of one form of an aspirator embodying the invention, with parts broken away for clarity of illustration of the two valves and the primary fluid injector;

FIG. 2 is an end elevational view of the aspirator shown by FIG. 1;

FIG. 3 is a fragmentary horizontal sectional view of the aspirator shown by FIGS. 1 and 2, showing both stages active;

FIG. 4 is a fragmentary horizontal section of such aspirator with only the first stage active;

FIG. 5 is a graphical illustration showing the pressure-flow characteristics of such aspirator;

FIG. 6 is a longitudinal sectional view taken along the line 66 of FIG. 7, illustrating another form of two stage aspirator embodying the invention;

FIG. 7 is a fragmentary plan of the aspirator form shown in FIG. 6;

FIG. 8 is an enlarged, longitudinal sectional view of another modified form of the invention, taken substantially along the line 88 of FIG. 10;

FIGS. 9A and 9B are schematic operational elevations of the FIG. 8 form of aspiration; and

FIG. 10 is an end elevational view of such latter form of aspirator.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, the embodiment shown in FIGS. 1-4 includes an inlet manifold 15 which is connected to a source of high pressure fluid by 'a pipe 16. Preferably the source is a cool gas generator such as, for example, the type disclosed in the patent to Heberstreit et 211.; 3,122,181. Other gas sources, such as compressed air, may also be suitable in some installations.

The fluid is discharged through a plurality of orifices 17 into a first stage nozzle 18, the downstream end of which is initially closed by an inner or circular check valve 20. A second stage nozzle 22 is positioned downstream of the first stage nozzle and has an air intake opening closed by an outer or annular check valve 24. As is best shown in FIGS. 3 and 4, the gas streams formed by the orifices entrain air into the first stage nozzle from which the mixture of gas and air is discharged as a combined fluid stream into the second stage nozzle and becomes the aspirating fluid for the second stage. Inflation takes place at a rapid rate due to the high volume of air discharged from the second stage. When the pressure builds up in the object to a predetermined level, the outer check valve is closed by back pressure and the object is further inflated by the first stage nozzle alone. When the object is substantially fully inflated,

gas flow is ceased and the back pressure in the object closes the inner check valve thus preventing deflation.

The first stage nozzle 18 has a cylindrical throat 26 formed integrally with a smoothly rounded, diverging flange 28 that defines an air inlet 29. The inlet manifold extends diametrically across the air inlet and is secured to the flange to provide structural strength. The orifices 17 are aligned diametrically on the downstream side of the manifold.

The second stage nozzle 22 includes a cylindrical throat 30 integrally formed with a rounded, outwardly diverging inlet flange 32 that defines a second air inlet 33. An annular mounting ring .34 is secured to an inlet flange and is secured to the fabric 38, or the like, of an object to be inflated, such as an airplane escape chute, for example. The second stage nozzle is connected to the first stage nozzle by three equidistantly spaced struts 40 that are secured, as by welding, to the second stage inlet flange and the outside surface of the first stage nozzle throat 26. The inlet flange 32 is provided with an inwardly directed peripheral lip 42 that serves as a valve seat in a manner to be hereinafter described.

The inner check valve is best shown in FIG. 1 and includes a circular resilient plate member or flap 44 of neoprene, rubber, or other flexible material and is of a diameter slightly greater than the inside diameter of the throat 26. A pair of centrally bored bosses 46 are bonded or otherwise secured to the downstream surface of the resilient plate 44 and are aligned along its vertical diameter. The bosses receive a pin 48 which is secured in spaced holes 50, by any suitable means, in the throat of the second stage nozzle 22. The pin serves as a support about which the side segments of the resilient plate 44 may pivot. A pair of semi-circular strengthening members 52 are secured, as by bonding, to each side of the downstream surface of the resilient plate 44. These members 52 are preferably of aluminum or any other suitable relatively rigid material. Each member 52 extends radially outwardly almost to the peripheral edge of the resilient plate 44. In effect, the check valve amounts to two resilient, hinged rigid flaps with a peripheral sealing edge.

The outer check valve 24, which closes off the second air inlet 33, includes an annular resilient, flexible plate 54 of the same flexible material as the circular plate 44. A pair of centrally bored bosses 56 are bonded to the downstream surface of the annular plate 54. The bosses are diametrically aligned and receive the pin 48. A pair of semi-annular strenghtening members 58 are secured, as by bonding, to the downstream surface of the annular plate 54 and extend almost to the inner and outer edges of the annular plate 54. These members 58 function in the identical manner as themembers 52. The upstream outer peripheral edge 60 (FIG. 4) of the annular plate 54 abuts against the lip 42 of the inlet flange 32. The inner edge 62 of the annular plate 54 extends radially inwardly beyond the inner circumferential surface of the throat 26 of the first stage nozzle 18 and serves as a seat for the inner valve 20. As is best shown in the operational views of FIGS. 3 and 4, when air is being aspirated in both stages, the annular circular plates are folded downstream. As the object is filled a back pressure is developed, and eventually it closes the annular plate 54 and the second stage of the aspirator ceases to operate. Inflation is then completed by the primary aspirator alone. Following completion of the inflation the inner circular plate 44 is also closed by back pressure and it and the annular valve 24 function as check valves to hold the fluid in the object.

The effect of the two-stage aspiration is best shown in FIG. 5, wherein the line ABD represents the flow rate of the combined first and second stages if no second stage shutoff valve were to be provided. This line shows that a high volume of mixed air and gas is initially introduced into the object but that pressure never exceeds 2 p.s.i.g. The lines shown in the graph of FIG. 5 actually represent a mass flow ratio rather than a flow rate. It is customary in the art, however, to discuss gas flow in terms of rate and it also provides a clearer understanding of the invention. The ratios shown in FIG. 5 are directly related to the flow rate for a constant flow of aspirating fluid o As an example, assume the aspirating fluid source produces a supply of aspirating fluid o at a constant rate of one pound mass per second. If the second stage is being used, that is as indicated by the line ABD, the initial mass flow rate of aspirated air is at a ratio of 3.2 and thus is 3.2)(1 pound mass per second yielding a total fluid flow rate of approximately 4.2 pounds mass per second. At a ratio of 1 along the same line ABD the aspirated air flow rate is also 1 pound mass per second so that the total flow rate at this ratio is 2 pounds mass per second. This convention of referring to flow rate rather than to ratio will be followed throughout the following description. In the embodiment just described, the area of the air inlets of the combined nozzle stages is approximately 4 /2 times the area of the air inlet of the first stage nozzle alone.

The line EBC represents the flow rate if only the single stage were to be used, as was heretofore customary. The single stage can reach a significantly greater pressure. However, the initial flow rate is substantially less than with two stages.

By the use of the check valve 24 in the second stage nozzle 22 the flow rate curve follows the solid line ABC. Thus, a high volume initial flow rate is produced up until point B where the back pressure is suflicient to close the outer check valve 24. The curve then follows the flow rate for the single stage nozzle reaching a pressure of over 4 p.s.i.g. in the example presented. Since the rfirst 60% of inflation is at a pressure slightly greater than atmospheric, the large volume will greatly increase the speed at which this amount of inflation is reached. For example, in the installation to which the graph relates the initial use of the second stage reduced the time of filling from 5 to 3 seconds or a percentage increase of 40%.

The aspirator shown in FIGS. 6 and 7 is in many respects similar to the above-described embodiment. It includes a first stage nozzle 70 having a cylindrical throat 72 and a smoothly curved, outwardly diverging inlet flange 74. A second stage nozzle 76 is provided with a cylindrical throat 78 and a smoothly curved, outwardly diverging inlet flange 80. The second stage inlet flange circumscribes the cylindrical throat of the first stage nozzle. The first stage nozzle is supported therein by four crossed tubular supports 82 having orifices 83 and which form a gas inlet manifold 84. The tubular supports are joined at their midpoints and are joined at their ends by an annular tube 86 that is connected to a supply pipe 88. The pipe 88 is connected to a suitable source of high pressure gas. The annular tube 86 is integrally formed on the air inlet flange of the second stage nozzle to serve as a rigid support for the first stage nozzle. The outer peripheral edge of the inlet flange 82 is secured to the fabric, not shown, of the object to be inflated.

As in the embodiment shown in FIGS. 1-4, the nozzles 70 and 76 are each provided with a check valve. The first stage nozzle 70 has a check valve 90 which includes a rigid conical plate 92 that seats against a seal ring 94 mounted on the inlet flange 74. A coil spring 96 is secured, as by welding, to the downstream surface 98 of the conical plate. The downstream end of the spring is secured in a piston 100 that is slidably mounted in a cylinder 102. The cylinder 102 communicates with the inlet manifold 88 through a passage 104 in one of the tubular members 82. Pressurized gas within the tubular members causes the piston to move the conical plate 92 to the right, as viewed in FIG. 6,-thus opening the check valve for the admission of air. The spring is calibrated to open the plate by a force slightly greater than the back pressure exerted on the face of the plate when the object is filled. Thus, the valve also acts as a relief .5 valve to prevent over pressurization of the object when filled.

The second stage nozzle 78 is also provided with a check valve 108 which is in the form of a truncated cone 110 of a flexible, resilient material, such as neoprene or rub her. The cone is fastened at its upstream edge to the outside surface of the cylindrical throat 72 of the first stage nozzle 70. Four stiffening bars 112 are equidistantly spaced withinthe truncated cone and are welded at their upstream edges to the inside surface of the cylindrical throat 72. These stiffening bars extend downstream a substantial distance and diverge outwardly toward the inside surface of the cylindrical throat 78. These bars 112 provide rigidity to the flexible material of the cone 110 to assist in maintaining the downstream end of the cone 110 normally biased outwardly tightly against the inside surface of the cylindrical throat 78. However, when the downstream pressure in the second stage nozzle falls below atmospheric, the incoming air flexes the cone inwardly. When the pressure in the object increases to a superatmospheric level the downstream end of the cone is flexed outwardly to seat against the inner wall of the second stage nozzle and stop the flow of ambient air into the second stage.

The operation of the embodiment shown in FIGS. 6 and 7 is basically identical to that shown in the first described embodiment. When gas is introduced through the manifold 84 it creates a pressure in the cylinder 102 to open the first stage check valve 90. Air aspirated through the inlet flange 74 of the first stage nozzle is entrained in the stream of gas and the combined fluid stream acts as an aspirating fluid for the second stage nozzle 76. At this time the object is just beginning to inflate and both stages are active to rapidly inflate the object. When the object reaches a predetermined pressure the back pressure will close the second stage check valve 108 and further pressurizing will be by the first stage nozzle alone. Once the object is inflated and primary gas flow ceases, the first stage check valve 92 is also closed by back pressure.

The embodiment shown in FIGS. 8-10 is also similar to the embodiment shown in FIGS. 1-4; however, it includes advantageous features for compact storage. This embodiment includes a first stage nozzle 120 shown in a retracted position in FIG. 8 and a second stage nozzle 122. The first stage nozzle includes a cylindrical throat 124 that is slidably mounted in rigid inner ring 126. An inlet manifold 128 is integrally formed on the cylindrical throat 124 and includes an annular tube 130 having a radially inner wall 132 that diverges smoothly outwardly from the cylindrical throat to form an air inlet. A pipe 133 connects the manifold to a suitable supply of pressurized gas. The inlet manifold also includes a radially outer extension 134 that has a flexible rubber debris and moisture seal 136 attached to its outer periphery. A pair of cross tubes 138 having downstream orifices 140 communicate with the annular tube 130.

The second stage nozzle 122 includes a cylindrical throat 142 integrally formed with a rigid outer ring 146 that diverges smoothly outwardly at its upstream end to form an inlet flange 148. A plurality of spaced radial arms 149 support the rigid inner ring 126 centrally in the rigid outer ring. The inlet flange also serves as an entrance for aspirated air and as a seat for the debris seal 136. An annular plate 150 is secured to the inlet flange and, at its outer peripheral edge to the fabric 152 of an inflatable object, not shown. An outer cylindrical extension 154 is slidably mounted on the cylindrical throat 142 and is shown in its retracted position in FIG. 8. The extension is biased to the left, as viewed in FIG. 8, by a plurality of spring strips 156, best shown in the operational views 9A and 9B. A catch 158 holds the cylindrical extension in its retracted position and includes a rod 160 twisted about a pivot pin 162 mounted on a boss 164 that is secured to the inside surface of the cylindrical throat 142. The rod has an outwardly curved tip 166 that, in its operative position, extends radially outward beyond the downstream edge of the cylindrical extension 154. The other end of the rod, in its operative position, abuts against a downstream surface of a check valve, to be later described, fastened to the downstream end of the cylindrical throat 124 of the first stage nozzle 120. Four such catches are provided. As can be readily seen from FIG. 8 the first stage nozzle maintains the rod in engagement with the downstream edge of the cylindrical extension. When the cylindrical throat of the first stage nozzle is moved to the right, as viewed in FIG. 8, the rod is released and the springs 156 move the cylindrical extension 154 to the left while simultaneously rotating it into the position shown in phantom lines in FIG. 8.

The first stage nozzle is provided with a check valve 168 which is similar to the check valve 20 shown in the embodiment of FIGS. l-4. The valve includes a pin 170 secured to the cylindrical throat 124 by any suitable means. The pin is received in a diametrical boss 172 secured to the upstream surface of a circularflexible plate 174. The circular plate is made of a resilient material, such asrubber, and seats against the downstream edge of the cylindrical throat 124. A pair of stiffening members 176, of aluminum or the like, are bonded to the downstream surface of the flexible plate. The members are identical in shape and function to the strengthening members 52 of the check valve shown in the embodiment of FIGS. 1-4. The flexible plate acts like flaps and since the valves in the two embodiments are substantially alike both in structure and function, no further description is believed necessary.

The second stage nozzle 122 is also provided with a check valve 178 that includes a pair of diametrically opposed pins 180 secured by any suitable means in the downstream ends of the rigid inner and outer rings 126 and 147. The pins are received in a pair of bosses 184 secured to the upstream surface of an annular flexible plate 186. The annular plate 186 is also of a resilient material, such as rubber, and seats against the downstream edges of the rigid inner and outer rings. A pair of stiffening members 188 are bonded to the downstream surface of the annular flexible plate. The flexible plate of the check valve 178 functions like flaps in substantially the identical manner as the check valve 24 of the embodiment shown in FIGS. 1-4 and accordingly no further description is believed necessary.

In the operation of the embodiment. shown in FIGS. 8-10 the two-stage aspirating technique is identical to that of the embodiment of FIGS. 1-4. The extension features of this embodiment improve the flow and mixing characteristics of the nozzles and function in the following manner. The gas emitted from the orifices 140 reactively moves the cross tubes 138 to urge them to the right, as viewed in FIG. 8, into the phantom position. The catch 158 is released and the springs 156 extend the cylindrical extension 154 to the left. After the object is inflated, the cylindrical extension and the first stage nozzle remain in their extended positions since it is no longer essential that they be in a compact form.

While the invention has been described in its preferred non-limiting forms, it is understood that changes may be made without departing from the principles of the invention. It is to be understood, therefore, that the scope of the invention is to be determined solely by the proper interpretation of the claims appended hereto.

What is claimed is:

1. A two-stage aspirator comprising:

a first stage tubular nozzle defining a first stage flow passageway having an inlet for ambient air and an outlet;

means for introducing an aspirating fluid stream generally axially into said first stage flow passageway;

a larger second stage tubular nozzle having an inlet end receiving the outlet of said first stage flow passageway, and together with said first stage nozzle defining, a second stage flow passageway for ambient air which at least partially surrounds said first stage flow passageway; and

valve means for preventing any back flow through said aspirator, said valve means including a first double flap valve movable between an open position wherein the flaps are generally contiguous and aligned with the flow and a closed position wherein said flaps extend generally transversely across said first stage flow passageway, and a second double flap valve movable between an open position wherein the flaps are generally contiguous and aligned with the flow and a closed position wherein said flaps extend transversely across the [inlet of said] second stage flow passageway 2. A two-stage aspirator comprising:

a first stage tubular nozzle defining a first stage flow passageway having an inlet for ambient air and an outlet;

means for introducing an aspirating fluid stream generally axially into said first stage flow passageway;

21 larger second stage tubular nozzle having an inlet end receiving the outlet of said first stage flow passageway, and together with said first stage nozzle defining a second stage flow passageway for ambient air which at least partially surrounds said first stage flow passageway; and

valve means for preventing any back flow through said aspirator, said valve means including separate check valves, each including a resilient plate member and a set of stiffening members fastened to its plate member on opposite sides of a non-stiffened center strip, and a mounting pin fastened to each center strip, whereby the non-stiffened center strip of each plate member functions as a hinge means, parmitting a pivotal folding together of the stiffened portions of each plate member.

3. The aspirator of claim 1, wherein said first double flap valve includes a plate having a resilient central hinge portion, and means secured to said hinge portion for connecting said plate to said first stage nozzle.

4. The aspirator of claim 3, wherein said means for introducing a stream of fluid axially into said first stage flow passageway includes a tubular member extending across the air inlet of said first stage flow passageway, said tubular member having a plurality of orifices positioned on opposite sides of said means for connecting said plate to said first stage nozzle means.

5. The aspirator of claim 1, wherein said first and second double flap valves are generally coplanar, said second double flap valve extends about the first, and said first double flap valve has a peripheral sealing edge that seats against said second flap valve.

6. An inflation aspirator for an inflatable object comprising:

nozzle means communicating with the interior of the object, said nozzle means being movable at least partially into the object for stowage, and extendable outwardly of the object for use;

injector means for supplying a stream of aspirating fluid axially into said first nozzle means; and

second stage nozzle means arranged to receive the eflluent of said first nozzle means, and to discharge into the object,

said second stage nozzle means being extendable inwardly of said object.

7. The aspirator of claim 6, wherein said nozzle means are each provided with an air inlet and closure means.

8. The aspirator of claim 6, further including means for biasing said second nozzle means into its extended position and catch means for holding said second nozzle means in its retracted position, said catch means being releasable in response to outward movement of the first nozzle means.

9. The aspirator of claim 7, wherein said closure means includes an annular check valve for closing-oif the inlet of said second nozzle means and a circular valve closingofl the exit of said first nozzle means.

10. The aspirator of claim 6, wherein said first nozzle means is telescopically received in said second nozzle means.

11. A two-stage inflation aspirator for a gas confining type inflatable object comprising:

a first stage tubular nozzle defining a first stage flow passageway into said inflatable object having an inlet for ambient air and an outlet;

means for introducing an aspirating fluid stream generally axially into said first stage flow passageway;

a larger second stage tubular nozzle having an inlet end receiving the outlet of said first stage flow passageway, and together with said first stage nozzle defining a second stage flow passageway for ambient air which at least partially surrounds said first stage flow passageway; and

valve means for preventing any back flow through said aspirator, said valve means including a second stage valve for closing said second stage flow passageway only during one period of aspirator use, enabling use of the first stage passageway alone in such period.

12. The aspirator of claim 11 wherein said valve means further includes a valve for closing said first stage flow passageway alone.

13. The aspirator of claim 11 wherein said valve means further includes a first stage valve for closing said first stage flow passageway alone and wherein said first stage and second stage valves include separate check valves, each check valve including a resilient plate member.

14. The aspirator of claim 11 wherein said valve means includes a spring biased valve for closing the inlet of the first stage nozzle.

15. The aspirator of claim 11 wherein said second stage valve comprises a check valve in the form of a flexible truncated cone.

16. An inflation aspirator for a gas confining inflatable object having an outer fabric, comprising:

inlet structure including nozzle guide means secured to said fabric, tubular nozzle means slidably received in said guide means for movement relative to said fabric and communicating with the interior of the object and having a predetermined length, said nozzle means being at least partially movable into the object for substantially its entire length for stowage, and extendable outwardly of the object for a substantial portion of its length when in use; and

injector means for supplying a stream of aspirating fluid axially into said nozzle means.

17. The aspirator of claim 16, wherein said guide means permits the nozzle to be reactively extended by the initial supply of aspirating fluid discharging from said injector means.

18. An inflation aspirator comprising an inlet tube for a gas confining type inflatable object having an ambient air inlet and a combined fluid outlet, an injector for delivering an aspirating fluid into said inlet tube of said inflatable object, and the improvement comprising:

tubular wall means dividing the interior of the inlet tube into first and second stage passageways, each having an ambient air inlet, with said injector being positioned to discharge directly into the first stage passageway, and with said first stage passageway being positioned to discharge generally axially into said inlet tube at a location bounded by said second stage passageway, so that the mixture of aspirating fluid and aspirated ambient air discharging from said first stage passageway functions as an aspirating fluid for causing second stage aspiration in the second stage passageway, and check valve means in said second stage passageway, arranged to close in response to a predetermined back pressure in the inflatable object and in that manner render the second stage of the 2,096,226 10/1937 Crosthwait 230-92 aspirator ineffective, with inflation thereafter being 2,296,122 9/1942 Squassoni 230-45 completed by the first stage of the aspirator alone. 2,399,670 5/1946 Freygang 230-92X 19. An inflation aspirator according to claim 18, where- 2,887,120 5/ 1959 De See 137-223 in said first stage passageway is located radially inwardly 5 3,042,290 7/1962 Fraebel 230-95 of said second stage passageway and a tubular wall sepa- 3,204,862 9/ 1965 Hadeler 230-95 rates the two passageways, and said check valve is a 3,338,266 8/1967 Zilka et a1 --103-263X plural leaf flap valve supported in the second stage pas- 3,358,909 12/1967 Mansson et a] 230-45 sageway radially outwardly of said tubular wall. 3,370,784 2/ 1968 Day 137-223 X 20. An inflation aspirator according to claim 19, fur- 10 3,395,647 8/ 1968 Clabaugh 103-272X ther including a second plural leaf flap valve positioned in the first stage passageway, and arranged to close in DONLEY STOCKING, Primary Examiner response to back pressure when the inflatable object is I. KRAUSS Assistant Examiner sufficiently inflated.

15 U.S. Cl. X.R.

References Cited UNITED STATES PATENTS 1,367,208 2/1921 Schmidt 103-258 

